The use of thermoplastic polymeric material to package articles, primarily individual articles, is old in the art. The conventional method of packaging articles in a thermoplastic polymeric material is to place the article to be packaged or protected in spaced relation to the walls of an outer shipping container such as a corrugated container, fill the entire void volume between the article and the container walls with the thermoplastic polymeric material and then allow the material sufficient time to cure and set. To retrieve the encapsulated article after shipment normally required the destruction of the envelope of formed thermoplastic material. In any case, there was little if any attempt to reuse the material and so the conventional method involved considerable cost in terms of material as well as waste and was useful only to protect costly and easily damaged articles.
For example, U.S. Pat. No. 4,136,141 issued to U. Bauer et al. discloses a method for packaging an article to be shipped comprising an outer container into which the article is placed in spaced relation to the walls of the container. A flexible envelope is placed around the article and is then filled with a foamed cellular plastic material which sets up around the article to protect it.
To reuse the plastic material one could make use of the teachings in U.S. Pat. No. 3,222,843 issued to M. Schneider. In the Schneider patent, the article to be packaged or protected is placed in spaced relation to the walls of an outer shipping container and is spaced from the bottom wall by means of a pre-cut support. The remaining space between the article and the container walls is filled with foamed material that is poured into a pair of oppositely disposed flexible bags. The foamed material fills the bags and pushes the walls of the bags up against the article and the outer container in order to take the shape of the article to be shipped when the foamed material sets upon cooling. The resulting package can be easily reused since the two flexible bags are now filled with a formed thermoplastic material that is shaped to fit around the article to be shipped and any other articles of that same shape.
A method and apparatus for forming a protective packaging similar to that disclosed in U. Bauer et al. and M. Schneider, supra is disclosed in Windecker, U.S. Pat. No. 3,666,850 in which an apparatus delivers heat expandable thermoplastic materials to surround an article to be shipped, and at the same time heats the thermoplastic material such that they expand and adhere together and form a solid body around the article.
Another reusable shipping device is disclosed in U.S. Pat. No. 3,590,939, issued to J. C. Wittwer showing a protective bottle display and shipping container that is molded around an article to be shipped and can be re-used in shipping that article or one of a similar shape. Wittwer discloses a clear plastic container that is molded over a shape that is similar to the article to be shipped and then has the shape removed, leaving the empty space. The article to be shipped is then placed in the container and a bottom element is secured over the opening to retain the article in the container. The outer walls of the container are spaced away from the article such that any impact or shock experienced during shipment can be absorbed in these outer walls and thereby prevent damage to the article.
There are also a number of patents directed to a means for opening a formed plastic package made from thermoplastic material in order to extract the article shipped. Obviously, the package formed according to the method disclosed in Schneider does not require any additional device to open it. However, for a molded plastic protective package formed according to the teachings of Windecker, or Bauer et al., supra, U.S. Pat. No. 3,870,741 issued to G. B Kuhn discloses a method for making a foam package that includes a tear strip to facilitate removal of the article to be shipped.
All of the above-described methods for packaging are, practically speaking, limited in application for use with delicate and expensive items which can better bear the inordinate cost. Thus, while the protective qualities of packages employing the technology of forming molded-in-place supports for articles to be shipped might be beneficial in connection with less expensive items, heretofore the cost has been prohibitive.
In addition, the cost of shipping is such that most inexpensive items need to be shipped in groups as they could not be economically packaged individually. Therefore, a manufacturer will usually provide protection for the articles from ordinary shipping damage and also from damage caused by mutual contact, i.e., abrasion, denting, breakage. The most widely used of such protective devices are container inserts such as dividers, perimeter pads and the like. However, the use of dividers and perimeter pads is also costly in that they require additional materials and complex equipment for assembly, set-up and handling of the articles to be shipped.
Therefore, it is an object of this invention to provide, at minimal cost, a package for an array of articles to be shipped in which the articles are supported and separated without the use of dividers, perimeter pads or the like and yet protected from many common causes of damage that occur during shipment.
Another object of the invention is to provide a novel method for packaging an array of articles to be shipped in containers, boxes or similar shipping devices, by using a foamed-in-place polymeric material.
Yet another object of the invention is to provide a reusable, molded tray associated with the container, box or similar shipping package to provide support and separation of an array of articles to be shipped.
Still another object of the invention is to provide cut case protection for the articles to be shipped and to provide a tray that can be used for display purposes.
Still another object of the present invention is to provide a method which ensures a satisfactory packaging means for an array of articles of any size or shape.